Phosphate enriched manure fertilizer and method therefor including free amino acid supplementation

ABSTRACT

Phosphate enriched, potassium supplemental manure product and method of production including reaction of manure with a solution of alkali metal acid phosphate salt in orthophosphoric acid, in some cases with prolonged reaction at elevated temperatures to hydrolyze manure protein to free amino acids.

BACKGROUND OF THE INVENTION

A phosphate enriched manure fertilizer is prepared by reaction of manurewith an acid phosphate reactant comprising phosphoric acid such asorthophosphoric acid and an acid phosphate salt such as and particularlymonopotassium acid phosphate.

In particular embodiments the invention further relates to the mineralsupplementation of manure fertilizers by the addition of phosphate andby the addition of potassium.

In further embodiments of the invention, the reaction of phosphoric acidwith manure is continued at elevated temperatures and for a prolongedperiod and in the presence of a buffering quantity of alkali metal acidphosphate salt, effecting hydrolysis of the protein content of themanure and the generation of free amino acids.

The invention further relates to method for production of phosphateenriched manure, potassium enriched manure, and free amino acidcontaining manure fertilizer products.

PRIOR ART

Mineral and element supplementation of manures is known. A variety ofmaterials have been used including in some instances phosphoric acid andalternatively in the prior art phosphate salts. Among the patents knownto applicants are U.S. Pat. No. 173,621 to Griffith, U.S. Pat. No.129,739 to Loewenstein, U.S. Pat. No. 1,703,504 to Walton et al, U.S.Pat. No. 47,610 to Baugh, U.S. Pat. No. 517,661 to Powter, U.S. Pat. No.673,167 to Giffen, and U.S. Pat. No. 1,420,596.

SUMMARY OF THE INVENTION

The invention has for its purpose the preparation of an improvedfertilizer material, one comprising manure as the basic ingredient andhaving provision for supplementation of the manure with mineral andelemental materials specifically phosphate and potassium known to bebeneficial to plant life and as well in certain embodiments theprovision of free amino acids which, as is known, are directlyassimmiable into the plant structure and which therefore are extremelyefficient in the soil in plant nutrition.

In accordance with the purposes of the invention there is providedmethod for the production of phosphate enriched high organic contentfertilizer comprising manure, including the steps of reacting the manurewith at least one part by weight of an acid phosphate reactant per onepart of manure, the reactant comprising a mixture of one part by weightof an alkali metal acid phosphate and from one to eight parts by weightof orthophosphoric acid, and recovering the product. In preferredembodiments the salt is monopotassium phosphate but the acid phosphatesalt may have the formula MeH₂ PO₄ wherein Me is an alkali metalselected from potassium, sodium, lithium and cesium. In otherembodiments the acid phosphate salt may have the formula Me₂ HPO₄ inwhich the metal is an alkali metal as mentioned. The orthophosphoricacid may be used as an aqueous solution containing about 85 percent byweight of the acid i.e. commercial orthophosphoric acid.

In certain embodiments it is preferred that the manure be first slurriedin water prior to effecting reaction with the acid phosphate reactant.

Accordingly and in preferred carrying out of the invention there isprovided method for the production of phosphate enriched high organicfertilizer comprising manure, including the steps of slurrying manure inup to five parts by weight of water per part of manure, mixing an acidphosphate reactant solution of one part by weight of monopotassium acidphosphate in from one to four parts of orthophosphoric acid with themanure slurry in an amount of one to four parts by weight of the acidphosphate reactant per part of manure and recovering the product.

In further embodiments of the invention three amino acids are generatedwithin the enriched manure fertilizer product. In this respect theinvention provides a method of producing free amino acids in thefertilizer product produced as above by heating the product at anelevated temperature above about 75° C for several hours and recoveringthe product. Typically, heating is continued for not less than 4 hoursand preferably heating is carried out at about 90° C.

Accordingly, in a preferred form of the process there is provided methodfor the production of free amino acid-containing phosphate-enriched highorganic content fertilizers comprising manure, including slurryingmanure in up to five parts by weight of water per part of manure, mixingacid phosphate reactant solution of one part by weight of monopotassiumacid phosphate with from one to four parts of orthophosphoric acid withthe manure slurry in an amount of one to four parts by weight of theacid phosphate reactant per part of manure, heating the resultingmixture at about 90° C for not less than 4 hours to hydrolyzeproteinaceous material in the manure into free amino acid, andrecovering as product a manure fertilizer containing free amino acid,and enriched with phosphate and potassium.

The invention further relates to the products obtained by the foregoingmethods.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In carrying out the invention use is made of manure i.e. animalexcrement widely found in rural areas where fertilizer is mostimportant. While manure is a natural fertilizer, it is desirable toaugment its action in fertilizing plants by the addition of mineral andelemental supplements. It is to this purpose that the invention isdirected. Specifically the invention provides for reacting manure withphosphoric acid in the first instance, but only in the presence of anacid salt of phosphoric acid whereby the reaction conditions areameliorated to an extent permitting the effective reaction of phosphoricacid with the manure fertilizer. In addition, particularly where theacid phosphate salt is the monopotassium or dipotassium acid phosphatesalt there is further added to the soil a quantity of potassium which isa necessary nutrient for plants.

As the phosphoric acid reactant we prefer to use orthophosphoric acidparticularly in its commercial form i.e. 85 percent H3PO4 in aqueoussolution.

As the acid phosphate salt reactant we prefer to employ an alkali metali.e. potassium, sodium, lithium, or cesium metal, mono- or di- acid saltas the salt reagent in the process.

In practice the manure is slurried in water to facilitate mixing of themanure and acid phosphate reactant. Typical proportions are for eachpart of manure from one to eight parts and preferably up to five partsby weight of water.

Following slurrying of the manure the acid phosphate reactant isprepared. Typically, this is accomplished by dissolving in phosphoricacid the particular salt e.g. and for illustrative purposesmonopotassium phosphate. The ratio of monopotassium salt as anillustration to phosphoric acid is in the range of, for each part ofmonopotassium acid phosphate salt, from one to four parts oforthophosphoric acid. In general, from one to four parts by weight ofthe acid phosphate reactant material comprising both the phosphoric acidand the acid phosphate salt is employed in the range of from one to fourparts of the acid phosphate reactant per part of manure in the slurry.

The reaction is generally effected at room temperature and proceedsnicely in an aqueous slurry of manure with the concentrations of acidphosphate reactant set out. After reaction, the reaction product isdried and may be applied directly as fertilizer for an improved resultin plant nutrition and soil supplementation.

As noted above, the invention further provides for the production offree amino acids within the modified fertilizer product prepared as justdescribed. For this purpose, the proteinaceous material within themanure is hydrolyzed under particular conditions leading to thegeneration of free amino acid. It is believed, while not wishing to bebound to any particular theory, that the hydrolysis of proteinaceousmaterial within manure produces usable free amino acids in the productwhile apparently similar processes do not, by virtue of the conjointpresence of both phosphoric acid and a complimentary phosphate salt suchthat the pH of the acid is buffered to approximately 25 percent to 50percent higher than the acid per se whereby hydrolysis proceeds even atthe elevated temperatures and for the prolonged heating periodsrecommended herein in such manner as to provide by virtue of thebuffered hydrolysis such amino acids as cuistein phosphate, argininephosphate, alanine phosphate, glycine phosphate, and histadinephosphate, and others.

It is noteworthy that in view of the buffered condition of the reactionsystem, amino acids generated are not destroyed and are thereby retainedfor use by the plant. It is known that amino acids may be directlyassimilated by the plants and therefore the nutritional effect isimmediate and remarkable.

The invention will be further described as to illustrative embodimentsin the following examples in which all parts and percentages are byweight.

EXAMPLE 1

Cow manure, one part by weight, was slurried with water, five parts byweight, and thereto there was added one part by weight of an acidphosphate reactant comprising 0.5 part by weight of monopotassium acidphosphate and 0.5 part by weight of orthophosphoric acid. The slurry andacid phosphate reactant solution were stirred together and the productrecovered by drying.

EXAMPLE 2

The reaction conditions of Example 1 were duplicated with the generationof free amino acids by heating the reaction product at 75° C for 4hours. There was produced a reaction product, which exhibited a positivetest for free amino acids.

EXAMPLE 3

Example 1 is duplicated employing four parts by weight of the acidphosphate reactant per part of manure.

EXAMPLE 4

Example 1 is duplicated employing as the acid phosphate reactantsolution one containing 0.5 part of monopotassium acid phosphate and twoparts of orthophosphoric acid. Results were equivalent.

EXAMPLE 5

Example 1 is duplicated employing eight parts by weight of water perpart of manure in slurrying the manure. Results were equivalent.

EXAMPLE 6

Example 1 is duplicated employing as the acid phosphate reactant an alsophosphoric solution of an alkali metal acid salt selected from sodium,lithium and cesium, mono- and dihydrogen acid phosphate salts. Resultswere equivalent.

EXAMPLE 7

Example 2 is duplicated using 90° C as the reaction temperature andheating for 4.5 hours. The reaction product tests positively for freeamino acid.

The products of Examples 1 through 7 are tested for fertilizingefficiency in a truck garden by blending into the soil at the level ofone bale per 1000 square feet the fertilizer products obtained. Gardenvegetables are grown in the area and the results observed. It is notedthat the plants are healthy, rapid growing and heavy bearing of fruit,the amino acid containing fertilizer areas having somewhat swifterresults.

We claim:
 1. Method for the production of phosphate enriched highorganic content fertilizer comprising manure, including reacting saidmanure with at least one part by weight of an acid phosphate reactantper one part of manure, said reactant comprising a mixture of one partby weight of an alkali metal acid phosphate salt and from one to eightparts by weight of orthophosphoric acid, and recovering the product. 2.Method according to claim 1 in which said salt is monopotassiumphosphate.
 3. Method according to claim 1 in which said salt is theformula MeH₂ PO₄ wherein Me is an alkali metal selected from potassium,sodium, lithium and cesium.
 4. Method according to claim 1 in which thesalt has the formula Me₂ HPO₄ in which Me is an alkali metal selectedfrom the group consisting of potassium, sodium, lithium, and cesium. 5.Method according to claim 1 in which said orthophosphoric acid is anaqueous solution containing about 85 percent by weight of the acid. 6.Method according to claim 1 including also preliminarily slurrying themanure in water.
 7. Method for the production of phosphate enriched highorganic content fertilizer comprising manure, including slurrying manurein up to five parts by weight of water per part of manure, mixing anacid phosphate reactant solution of one part by weight of monopotassiumacid phosphate in from one to four parts of orthophosphoric acid withsaid manure slurry in an amount of one to four parts by weight of saidacid phosphate reactant per part of manure, and recovering the product.8. Method according to claim 7 including producing free amino acids insaid fertilizer product by heating said product at an elevatedtemperature above about 75° C for several hours, and recovering theproduct.
 9. Method according to claim 8 in which heating is continuedfor not less than 4 hours.
 10. Method according to claim 8 in whichheating is carried out at about 90° C.
 11. Method according to claim 8in which heating is carried out at about 90° C for not less than 4hours.
 12. Method for the production of free amino acid-containing,phosphate-enriched high organic content fertilizers comprising manure,including slurrying manure in up to five parts by weight of water perpart of manure, mixing acid phosphate reactant solution of one part byweight of monopotassium acid phosphate with from one to four parts oforthophosphoric acid with said manure slurry in an amount of one to fourparts by weight of said acid phosphate reactant per part of manure,heating the resulting mixture at about 90° C for not less than 4 hoursto hydrolyze proteinaceous material in said manure into free amino acid,and recovering as product a manure fertilizer containing free aminoacid, and enriched with phosphate and potassium.
 13. Product produced bythe method of claim
 1. 14. Product produced by the method of claim 7.15. Product produced by the method of claim
 11. 16. Product produced bythe method of claim 12.